拟寄生物与寄主关系适合性的免疫学基础     

王小平  徐冠军 《湖北植保》1997,(5)

昆虫免疫是寄主昆虫抵御寄生物侵袭的一种防卫机制。寄主昆虫常通过被囊化作用来清除不适合的拟寄生物；相应地，拟寄生物逐步建立起一系列克服寄主免疫应答的策略，包括被动的和主动的策略。  相似文献   

Effect of eye fluke infection on the growth of whitefish (Coregonus lavaretus) —An experimental approach     

Anssi Karvonen  Otto Seppl 《Aquaculture (Amsterdam, Netherlands)》2008,279(1-4):6-10

Effect of the eye fluke Diplostomum spathaceum on fish growth has remained somewhat unclear because 1) the question has not been subjected to experimental examination with treatment-control setup and 2) growth has not been related to the coverage of parasite-induced cataracts in a quantitative manner. We examined effects of the parasite on growth and competitive ability of whitefish (Coregonus lavaretus) in experimental conditions resembling those at fish farms by maintaining groups of exposed and control fish, as well as mixed groups from both treatments, under optimal conditions for 8 weeks. Contrary to our expectations, we did not observe differences in fish growth between the treatments. However, at the level of individual fish, parasite-induced cataracts had a negative effect on weight of the exposed fish but this took place only when the cataract coverage reached 100% in both eyes. No effect of the infection on competitive ability of fish was observed in mixed treatments which may be related to patterns of food distribution in the tanks or cues received by the fish from less infected conspecifics. Overall, the results suggest that effects of D. spathaceum on fish growth become apparent only in cases of very high cataract coverage, and that feeding regimes and the shape of the cataract coverage distribution in a fish group are important determinants of the magnitude of these effects.  相似文献   

Green tea flavan-3-ols and oligomeric proanthocyanidins inhibit the motility of infective larvae of Teladorsagia circumcincta and Trichostrongylus colubriformis in vitro     

Molan AL  Sivakumaran S  Spencer PA  Meagher LP 《Research in veterinary science》2004,77(3):239-243

The effects of a hot water infusion and an aqueous acetone extract of green tea (Camellia sinensis) on the motility of infective larvae of the sheep nematodes Teladorsagia circumcincta and Trichostrongylus colubriformis were investigated under in vitro conditions. The infusion and extract dose-dependently inactivated the infective larvae as assessed by the larval migration inhibition (LMI) assay. To determine the components responsible for the inhibitory activity, the hot water infusion and aqueous acetone extract of green tea were fractionated on Sephadex LH-20 and the green tea extract fractions (GTE-I-VIII) characterised by mass spectrometry. The larvae were exposed to increasing concentrations of these GTE fractions. Fractions containing epigallocatechin gallate (EGCG) and proanthocyanidin oligomers were most effective. GTE fractions were more effective against T. circumcincta than T. colubriformis larvae as assessed by the LMI assay.  相似文献   

Anthelmintic resistance in non-strongylid parasites of horses     

Reinemeyer CR 《Veterinary parasitology》2012,185(1):9-15

Since 2002, selected populations of Parascaris equorum in several countries have been reported to survive treatment with macrocyclic lactone (M/L) anthelmintics. Clinical treatment failures are characterized by negligible fecal egg count reduction, but M/L resistance has been confirmed in ascarids by controlled efficacy testing. Resistance was selected by current parasite control practices for foals, which often include exclusive and excessively frequent use of M/L dewormers, thereby minimizing refugia within the host and in the environment. Chemical control of M/L-resistant isolates can be accomplished with pyrimidine and/or benzimidazole anthelmintics, but a few M/L-resistant populations have recently exhibited resistance to pyrantel pamoate as well. Some specimens of Oxyuris equi regularly survive treatment with macrocyclic lactones, but it is uncertain whether this constitutes resistance or merely confirms the incomplete oxyuricidal efficacy of virtually all broad spectrum equine anthelmintics. Variations in other biological parameters of Oxyuris and Parascaris, specifically atypical infection of older hosts and shorter prepatent periods, have been reported anecdotally. These changes may represent genetic modifications that have evolved in parallel with resistance as a result of anthelmintic selection pressure.  相似文献   

Setting the Stage for Long-term Reproductive Health     

Craig A. Payne  Brian Vander Ley  Scott E. Poock 《Veterinary Clinics of North America: Food Animal Practice》2013

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观赏鱼常见寄生虫病的诊治初探     

杨舒婷  杨志彪 《中国动物传染病学报》2013,(5)

观赏鱼资源丰富,却常发生寄生虫病,给水族爱好者带来较大的损失。本文通过对病鱼或死鱼的临床检查、病理剖检及实验室检查,对常见的瓣体虫病、车轮虫病、小瓜虫病、指环虫病和本尼登虫病的诊断进行了初步研究,并在此基础上进行了治疗。结果表明,以上5种寄生虫病在症状上有很多相似之处,只有经过刮片镜检,才能准确诊断。当鱼体诊断出有寄生虫时要迅速用硫酸铜、甲醛、吡喹酮和黄药粉等高效药物进行治疗。  相似文献   

寄生虫基因组研究进展     

梁宝  王国永  胡丽霞 《中国兽医寄生虫病》2008,16(5):36-41

基因组测序计划以及有关的转录组和蛋白质组图谱计划已经给寄生虫学的研究带来了一场革命。随着越来越多种类的寄生虫基因组序列被测定,通过系统的比较和分析基因的序列使得预测基因和功能验证的准确性越来越高,也为人们认知寄生虫的生物学特征、为人类和兽医筛选新的候选疫苗和药物靶标提供了重要数据。本文就寄生虫基因组研究进展作一简单综述。  相似文献   

福州动物园圈养鸟类肠道寄生虫调查     

曾菊英 《福建畜牧兽医》2016,(1):9-11

为调查福州动物园圈养鸟类消化道寄生虫感染情况,采集16种禽类31份粪便样品,应用饱和盐水漂浮法和自然水洗沉淀法收集虫卵,麦克斯特计数法对采集的粪便样本进行虫卵测定。检查结果显示,寄生虫感染阳性样品数有23份,占样品总数的74%。总共检出6种寄生虫感染,按感染例数从大到小排序为:球虫(9例)、吸虫(7例)、绦虫(6例)、线虫(5例)、鞭虫(4例)、纤毛虫(3例)。感染寄生虫的禽类中,孔雀的感染强度最高,EPG为9 150个/g;其次是巨嘴鸟,EPG为4 500个/g;第三是东方白鹳,EPG为3 300个/g。其他鸟类的EPG分布在0~2 100个/g。该调查结果为福州动物园圈养鸟类寄生虫病的防治以及制定科学的驱虫程序提供可靠的依据。  相似文献   

Species diversity and acquisition of gastrointestinal parasites in calves aged 0-13 months in periurban livestock production in Mali     

Wymann MN  Bonfoh B  Traore K  Tembely S  Zinsstag J 《Veterinary parasitology》2007,143(1):67-73

Post-mortem inspections on 51 calves were conducted to investigate acquisition and spectrum of gastrointestinal parasites in young calves in periurban livestock production in Mali. Generalized linear models with herd as a repeated effect were used to test the influence of management, age and season of birth on parasite numbers and diversity. Parasite number and burden increased with age. In the age class 4-13 months animals carried already up to eight different gastrointestinal parasite species. Parasite spectrum found included 11 nematodes, 3 cestodes and 1 protozoan parasite. The most frequent parasite species found were Haemonchus placei (age class 0-1 month: 7%, 1-4 months: 38%, 4-13 months: 69%), Cooperia pectinata (0%, 33% and 44%) and C. punctata (0%, 33% and 38%). Calves born during the rainy season had higher parasite burden and species diversity than calves born during the dry season. Calves kept under modernised management excreted more Strongyloides papillosus eggs than calves kept under traditional management. Calves acquired most of the parasites occurring in adult bovines in West Africa within their first year of life.  相似文献   

The relative resistance to gastrointestinal nematode infection of three British sheep breeds   总被引：1，自引：0，他引：1  

Nick Golding  Richard W. Small   《Research in veterinary science》2009,87(2):263-264

The relative resistance of Manx Loaghtan, Shetland and Southdown sheep to naturally acquired gastrointestinal nematode infection was assessed over a ten week period. Thirty shearling ewes, ten from each of the three breeds, were co-grazed on an infective pasture. The animals were initially treated with an anthelmintic to minimise previous nematode infection, and faecal samples were collected from individual animals every two weeks. Southdown sheep had significantly higher faecal egg counts (FEC) than Shetland by week 6, and than Manx Loaghtan by week 10. After ten weeks there was an 86-fold difference in FEC between Shetland and Southdown sheep, and a 14-fold difference between Manx Loaghtan and Southdown sheep. These preliminary results suggest that primitive Shetland and Manx Loaghtan sheep may have greater resistance to gastrointestinal parasites, a trait that could be of value to the UK livestock industry.  相似文献